LIVESTOCK PRODUCTION

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LIVESTOCK PRODUCTION

• LECTURE 8

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INTRODUTION

• Domestication of wild animals enabled people to
• Produce food i.e. meat, milk, cheese and other
  dairy products, eggs etc.
• Produce leather for clothing, shoes, bags and
  other by-products for the manufacture of glues,
  drugs, fertilizers etc.
• Provide means of transport e.g. camels, donkeys
  and horses.
• Provide farm power e.g. water buffaloes and
  bullocks for ploughing fields.

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Classification of Farm Animals

• Animals can be classified either
• Scientifically or
• According to their nutrition (feeding habits)
• Scientifically
• All common farm animals of the tropics except
  poultry and rabbits belong to the
• class Mammalia and
• order Artiodactyla.
• Cattle, sheep and goats belong to the family
  Bovidae whereas pigs belong to the family Suidae.

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Classification of Farm Animals

• Cattle belong to the Bos genus, the sheep belong
  the Ovis genus, the Goats to Capra genus and the
  pigs to Suis genus.
• The domestic rabbit belongs to the family
  Leporidae and is derived from the species
  Oryctolagus cuniculus.
• According to their nutrition farm animals can be
  grouped into
• Ruminants
• Non-Ruminants
• Herbivores

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Ruminants

• These are animals with a complex stomach of four
  compartments.
• One compartment is the rumen where the food that
  has just been eaten is temporarily stored.
• The cellulose in the plant cell walls is digested
  in the rumen by the rumen bacteria.
• From the rumen the food is passed into another
  compartment known as the reticulum.

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Ruminants

• From the reticulum, food is regurgitated back
  into the mouth where more chewing swallowing of
  the food occurs again.
• This process is referred to as chewing the cud.
• The other two compartments in which further
  digestion takes place are the omasum and abomasum

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Non-ruminants

• These are animals with one stomach compartment
  and omnivorous habits
• They include the pigs and poultry.
• Poultry describes all forms of domesticated birds
  including chickens, turkey, ducks, guinea fowl,
  pea fowl, pigeons, gees and ostriches.
• Pigs are particularly important in non-moslem
  countries where they are increasingly being
  reared under intensive conditions.

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Herbivores

• These are non-ruminant plant eaters
• They include
• Rabbits,
• Guinea pigs,
• Larger farm animals such as
• Camels
• Horses
• Donkeys
• The larger animals are used mainly for
  transportation and as farm power.

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Types and Classes of Domesticated cattle

• Cattle are categorized as
• Beef Cattle
• Dairy Cattle
• Dual purpose cattle
• Draught Cattle
• Beef Cattle
• These cattle are best suited for beef production
  having a great width and depth of body.
• The udder is usually poorly developed and little
  milk is produced.
• These animals are efficient in the conversion of
  feed into high quality beef for human consumption.

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Types and Classes of Domesticated cattle

• Dairy Cattle
• Have a lean angular frame with a well-developed
  mammary system, moderate girth and deep belly.
• One of the most important characteristic of dairy
  cattle is good temperament.
• Dual purpose cattle
• These are intermediate between beef and dairy
  cattle in conformation and performance.
• Many indigenous breeds in the tropics are used as
  beef, dairy and draught animals.

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Types and Classes of Domesticated cattle

• Draught Cattle
• These are characterized by great size and length
  of body and strength given by their rugged form.
• In many parts of the tropics, oxen are still used
  as a source of power for tilling the land.

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Adaptation of Livestock to Tropical Environments

• Early attempts to export temperate breeds of
  livestock met with dismal success.
• After a relatively short time in the tropics, the
  productivity of many breeds of exotic stock
  decreased, their condition deteriorated and they
  became susceptible to tropical diseases.
• In the recent years agricultural scientists have
  devoted attention to the subject of adaptation of
  livestock to hot climates.
• Thus the environmental physiology of farm
  livestock, the effects of solar radiation and
  heat stress on their productivity in tropical and
  subtropical areas have been well documented.

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Adaptation of Livestock to Tropical Environments

• The basic principles of thermal adaptation are
  common to all vertebrates.
• However different types of external covering
  (hair, wool, feathers and bristles) and the
  different types of underlying skin structure,
  give rise to variations in the mechanism of heat
  loss and the maintenance homeothermy (maintenance
  of an almost constant internal body temperature).

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Effects of Heat on Tropical Livestock

• A temperate animal taken to a hot climate is
  affected in two distinct ways.
• Directly by the influence of high temperature and
  intense radiation and possibly humidity on the
  animal itself
• Indirectly by the effect of heat on the animals
  environment including natural feed supply.

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Direct Effects of Heat

• Every vertebrate animal has a particular range of
  environmental temperature to which it is adapted
  and in which it is able to live most efficiently
  at minimal metabolic rate.
• This is what is referred to as the comfort zone.
• When animals are kept at temperatures below or
  above their comfort zones their metabolic rate is
  increased, either to keep the animal warm or to
  assist in heat dissipation.

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Direct Effects of Heat

• Evaporative losses of water from the body
  surfaces are the most fundamental processes
  concerned with heat regulation.
• At low environmental temperatures,
  non-evaporative cooling (i.e. loss of heat due to
  conduction, convection and radiation) is
  responsible for more heat loss than evaporative
  cooling.
• As the environmental temperature rises, the
  proportion of evaporative cooling rises and the
  proportion of non-evaporative cooling falls.

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Direct Effects of Heat

• The principal effect of sweating is to limit the
  rise in skin temperature.
• Since skin temperature largely governs
  respiration rate a high sweating rate will be
  associated with a relatively low respiration
  rate.
• The major ways in which animals adapt to tropical
  heat include
• Heat tolerance
• Coat characteristics
• Skin pigmentation.

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Heat tolerance

• A heat tolerant animal is one that has a high
  efficiency of energy utilization and allows
  productive processes to continue at high level
  without the production of excessive amounts of
  heat.
• Heat tolerance index is used to describe the heat
  tolerance range of different animal species.

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Coat characteristics

• The role played by the hair coat in thermal
  balance in a hot environment is twofold
• It affords a certain degree of protection against
  radiant heat from the sun.
• It interferes with the dissipation of heat from
  the animals body surface.
• The most important characteristics include
• Coat color
• Coat Texture
• Skin pigmentation

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Coat characteristics

• Coat colour is important in reflecting or
  absorbing solar radiation.
• Hair fibres which are light in colour reflect
  more solar radiation than hairs which are dark.
• The amount of sunlight reflected can be as much
  as 50 in the case of a white-haired animal, but
  considerably less with a dark-coloured animal.
• The coat colour is of much importance during
  periods of high light intensity (summer) than
  during periods of low light intensity (winter).

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Coat characteristics

• Coat Texture affects the mean absorption
  coefficient of animals.
• The rectal temperatures and respiration rates of
  Woolly-coated animals are invariably higher than
  those of animals with fine, glossy coats.
• The nature of the hair has a bearing on the
  insulative properties of the coat.
• Skin pigmentation
• A pigmented skin is most desirable in the tropics
  since it is less susceptible to sunburn and
  photosensitivity disorders.

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Indirect Effects

• The most important indirect effect of climate on
  tropical livestock is that associated with water
  requirement and feed intake.
• The quantity and quality of feed on offer to
  tropical livestock is primarily dependent upon
  the climatic factors influencing, and possibly
  limiting, plant growth.
• The second most important indirect effect of
  climate on farm animals is its influence on the
  distribution of the major pests and diseases and
  the arthropod vectors which are responsible for
  their spread.
• For example, the distribution of Tsetse fly is
  directly related to the presence or absence of
  suitable breeding sites, and these are themselves
  influenced by the climate of that region.

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Animal Feeding/Nutrition

• Animals require feed rations that are complete
  and balanced nutritionally.
• Each species and category of animal within a
  species has different nutritional requirements
  that must be calculated with care to ensure
  maximum productivity.
• The two main types of feedstuffs are
• Roughage, with high crude fibre content, and
• Concentrates with low crude fibre content.

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Roughage

• Roughage is fed fresh or in the form of hay or
  silage to supply some protein, energy, vitamins
  and minerals.
• The commonly used grasses are Guinea grass,
  Elephant grass and giant star grass.
• Maize, millet and sorghum are usually cut for
  making silage.
• The common legumes include clover.
• Concentrate feeds provide energy and protein
  needs.

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Forage Conservation

• The surplus grasses and cultivated crops produced
  during the growing season can be conserved a hay
  or silage to be utilized during the dry season
  when available grass becomes fibrous and
  unpalatable.
• Hay
• Forages are cut and dried naturally, by air and
  sun drying, or artificially.
• The forage is cut at sufficiently early stage of
  maturity to ensure nutritional excellence.
• Drying usually lowers the water content below 25
  so that the hay can be stored without becoming
  mouldy or fermented.

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Forage Conservation

• Hay
• Properly cured hay is close to the original
  forage in nutritional value.
• Silage
• Grasses and cultivated crops such as maize,
  sorghum and millet are conserved as silage by
  chopping them into pieces, placing them in a silo
  and compressing them sufficiently to exclude most
  of the air.
• Fermentation of soluble carbohydrates takes place
  producing organic acids, mainly lactic acid, with
  some ethanoic acid.

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Forage Conservation

• Silage
• The low pH of the mass prevents growth of
  undesirable bacteria that cause putrefaction
  (making it to go bad).
• Fermentation ceases after sufficient acid has
  been produced.
• The silage will keep for a long time with little
  change if stored in airtight bins and protected
  from rainwater.

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Animal Health

• Animal diseases and disorders cause considerable
  losses, which include
• Death of the animals
• Increased cost of production
• Lowered quality of meat, hides and skins
• Greatly reduced efficiency of animal production
• Some diseases and parasites are transmitted from
  animals to humans by contact, contamination of
  water or when a person eats food products from a
  diseased animal.

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Signs of ill health in farm animals

• Disease is any condition of the animal, which
  differs from normal health.
• All the vital processes of feeding, digestion,
  respiration, blood circulation movement and all
  related activities function satisfactorily in
  healthy animals.
• Departures from some or all of these processes
  indicate ill health.

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Signs of ill health in farm animals

• Signs of ill health in farm animals include
• Dullness.
• Restlessness or nervousness.
• Loss of appetite or complete avoidance of feeding
• Indiscriminate feeding
• Severe loss of body mass in severe cases
• Uncoordinated movement
• Death

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Signs of Good Health

• The state of health of an animal can be assessed
  from observations on
• Pulse Rate
• Body temperature
• Body Conformation
• Condition of skin or coat
• Visible mucous membranes
• Feeding habits

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Signs of Good Health

• Pulse Rate
• This is the rate and force of blood passing
  through the blood vessels per minute.
• This reflects the heart beat.
• The normal pulse rates per minute for cattle is
  50-70, for the horse is 28-42 and for the sheep
  is 68-90.
• When the pulse rate is outside the normal range,
  unless it can be explained physiologically (e.g.
  exercises increase rate) ill health may be
  suspected.

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Signs of Good Health

• Body temperature
• Normal body temperatures in C are
• Cattle 37.6-39
• Horse 37.5-38.3
• Sheep 38.3-39.3
• Pig 38.3-39.3
• Any change in temperature above or below the
  normal range may indicate ill health.

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Signs of Good Health

• Body Conformation
• Excessive fatness may result from overfeeding or
  disease while leanness or emaciation may be a
  result of under-feeding, starvation or disease.
• A normal animal usually shows the proportions or
  body organs and tissues characteristics of the
  breed or strain of the animal.

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Signs of Good Health

• Condition of skin or coat
• The skin of a healthy a normal is usually smooth
  and slips back easily when pulled.
• The hair is bright, clean and unruffled.
• Extremely dry hair or staring coat where the hair
  sticks up, are symptoms of ill heath.
• Excessive sweating causes the hair to form a mat
  on the skin and indicates ill health it is not a
  result of exercise.
• Similarly, loss of hair, abnormal out-growths or
  swellings of the skin, eruptions and boils,
  presence of parasites on or under the skin of
  animals are all signs of ill-health.

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Signs of Good Health

• Visible mucous membranes
• The inside linings of the eyelids, nose, mouth
  and the external urinogenital tract of normal
  animals are usually moist and pinkish.
• When an animal is ill, these linings may appear
  bright red or pale and anaemic or yellowish or
  bluish depending on the type of disease from
  which the animal is suffering.

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Signs of Good Health

• Feeding habits
• Healthy animals consume enough food when
  available according to nutritional needs.
• A sick animal may develop abnormal appetite for
  non-feed materials and eats anything
  indiscriminately.
• Healthy ruminants chew the cud in between feeding
  but sick animals do not and in some cases the
  animal may vomit the ingested feed.
• The consistency, texture, colour, smell and
  frequency of defecation or urination may also
  indicate ill health.

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Causes Diseases and Disorders

• Animal diseases and disorders can be caused by
  living organisms such as bacteria, fungi,
  viruses, nematodes and trematodes (helminthes),
  ticks, lice and flies and by non-living
  substances such as chemical poisons.
• Other causes include insufficient or poor-quality
  feed as well as deficiencies of nutrients such as
  carbohydrates, proteins, mineral elements and
  vitamins.
• Some diseases or disorders are due to one or more
  of these causes.

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Causes Diseases and Disorders

• Poorly fed animals are more prone to succumb to
  attacks by living organism.
• Under the traditional system of animal husbandry
  in the tropics, animals are poorly fed.
• A cause that excites a disease is always directly
  associated with it whereas a predisposing cause
  reduces an animals resistance to the exciting
  cause.
• The causes can be categorized as
• Physical causes
• Mechanical causes
• Chemical causes
• Biological causes

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Causes Diseases and Disorders

• Physical causes
• Abnormal ambient temperatures are important
  although in the tropics it does not fluctuate so
  much.
• Animals imported from temperate regions are most
  affected.

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Causes Diseases and Disorders

• Mechanical causes
• Pressure on body tissues from tumours or
  parasites, polyps (small growths) in the nose and
  urinogenital system are often disabling
  especially where they affect a vital organ such
  as the brain or liver.
• Obstruction of the air and food passages by feed
  or other materials or strictures of the orifices
  caused by contraction of the muscle or coats are
  other common mechanical problems.

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Causes Diseases and Disorders

• Chemical causes
• Retained waste products of body metabolism such
  as urea, other nitrogenous compounds or excessive
  carbodioxide can cause illness as well as
  poisonous substances such as acids and caustic
  alkalis.
• Heavy metals and animal toxins may be inhaled,
  ingested or taken in through the skin.

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Causes Diseases and Disorders

• Biological causes
• A large number of parasitic bacteria, fungi,
  viruses, protozoa, helminthes (worms) insects and
  ticks actively invade animal tissues and organs.
• These invasions result in localized or
  generalized disease conditions that may be fatal
  in very severe cases.
• Feeding animals on unbalanced feed or dirty water
  can cause nutritional deficiencies or introduce
  disease-causing organisms respectively.

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Diagnosis of Disease

• This is normally done by veterinarians through a
  combination of physical examination, observation
  of clinical symptoms and chemical and
  microbiological tests in the laboratory.
• The results give a basis for the application of
  preventive and curative measures to combat or
  control the disease.
• The carcass of a dead animal is examined for any
  signs of lesions of the killing disease in a
  post-mortem examination.

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Transmission of Disease

• Diseases are transmitted from one animal to
  another when pathogens escape from an infected
  animal and spread to healthy animals.
• Many disease-causing organisms are destroyed by
  the defensive mechanisms of the host,
• others are eliminated in its secretions and
  discharges and may invade other animals or
  re-infect the same animal.
• Thus an animal that dies from an infective
  disease should be properly disposed of by burning
  or burying the carcass deep in the soil.
• This ensures that the pathogens are destroyed and
  do not spread the infection.

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Transmission of Disease

• In some cases the pathogen and its host can
  co-exist so that the pathogen does not produce
  disease symptoms and the animals body does not
  destroy the pathogen.
• Predisposing factors such as poor nutrition or
  inter-current diseases can upset the balance and
  allow the pathogen to become infective.
• The animal then develops the disease symptoms.
• High levels of nutrition, management and
  sanitation help animals to resist invading
  pathogens.

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Sources of Infection

• The ways by which pathogens reach their hosts
  include
• Direct or immediate contact with other diseased
  animals resulting in the transfer of the disease.
  Skin diseases and some venereal diseases are
  transferred in this way.
• Indirect contact with objects such as dirty
  utensils, vehicles used to transport sick animals
  or railings in animal houses which may carry over
  pathogenic organisms from sick to healthy
  animals.
• Contact with symptomless carriers.
• Soil-inhabiting spores of some bacteria invade
  animals through wounds e.g. tetanus, anthrax and
  clostridial infections are often picked up by
  grazing or trekking animals.

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Sources of Infection

• Ingestion of contaminated feed.
• Airborne infection in overcrowded housing e.g.
  most respiratory diseases caused by bacteria,
  fungi or viruses.
• Blood-sucking and biting flies, fleas, lice and
  ticks transmit disease organisms through their
  bites. E.g. Trypanosomiasis, tick fever and some
  filarial infections.
• Condition loss due to stress.
• Some bacteria live in mucous membranes of animals
  without causing disease but in cases of stress,
  the organism becomes pathogenic.

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Routes of infection

• Main route of entry of parasites and pathogens
  into an animals body is through the organs and
  tissues of the animal including the alimentary
  canal, urinogenital organs, eyes, nose, and skin.
• The skin, which serves as a protective coat over
  the body organs and tissues, may become a route
  of entry for pathogens wherever it is
  mechanically damaged or weakened.
• Many fleas, ticks and lice attach themselves
  directly to the skin or merely live on the
  surface of the skin protected by the hair or the
  feathers. In sucking blood or biting the animal,
  they inject pathogens.
• Pre-natal and post-natal infections of young
  animals may occur through the placenta or poorly
  managed umbilical cords.

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Routes of infection

• Some pathogens of poultry can be transmitted
  through the egg from an infected hen.
• The respiratory tract, conjuctiva and mammary
  glands are also routes of infection.

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Disease Course

• After infection and before disease symptoms occur
  there is usually an incubation period.
• This is the time lag between the entry of the
  infective organism into the animal and the
  outward expression of signs of the disease.
• During this period the animal appears normal but
  it can infect other animals.
• Once the symptoms of a disease appear, the
  disease may progress rapidly into an acute
  condition, which may progress to death or
  recovery.
• In chronic cases, the disease persists for a long
  time and may or may not cause death of the
  animal.
• If the animal contracts another disease during
  this time, it may die after prolonged suffering
  and extensive loss of condition.

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Defense against Disease

• Normal animals protect themselves against disease
  by
• Primary defensive mechanism which hinder or
  prevent the entry of pathogens
• Secondary defensive mechanism which attack the
  pathogens which enter the body.
• The secondary defensive mechanism either prevents
  multiplication and spread of the pathogen in the
  animals body or inactive toxins produced by
  pathogen.
• The white blood cells can produce antitoxins
  against specific pathogenic secretions.
• This is what is referred to as immunity

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Defense against Disease

• Any foreign protein (antigen) entering an
  animals blood makes the white blood cells
  produce antibodies.
• These chemicals attack the antigen and immobilize
  or destroy it.
• The types of immunity include
• Natural immunity
• Artificial immunity
• Natural immunity
• The animals white blood cells have the ability
  to produce antibodies to some antigens before
  they are exposed to infection by those antigens.

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Defense against Disease

• Natural immunity may be
• Inherited
• Passively acquired through the colostrum and milk
  of the mother
• Actively acquired after infection whether or
  not the animal exhibits symptoms of the disease.

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Defense against Disease

• Artificial immunity
• Active artificial immunity is achieved by the
  injection of a non-pathogenic attenuated (reduced
  in strength) form or a small amount of the living
  pathogenic organism.
• Secretion of antibodies in response confers a
  state of immunity, which may be temporary or
  permanent.
• Usually the process is repeated periodically to
  ensure that the immunity does not fade away.

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Defense against Disease

• Passive artificial immunity is conferred by
  injecting serum obtained from an animal that has
  recovered from a disease into another animal that
  is susceptible to the same disease.
• The antibodies in the serum confer immunity to
  the recipient animal only for a short time.